Borderlands 2 Weekend Events

Gearbox Software announces that they are gearing up for next week's release
of the Krieg the Psycho character in Borderlands 2 with special in-game
events between now and then. They don't specify what these are other than to
mention increased drops and some heavier enemy populations:

Prepare for
the arrival of Krieg the Psycho -- the new playable character for Borderlands 2,
releasing May 14 -- with special in-game events from May 10 through the end of
May 13!

The Bandits of Pandora can feel one of their own approaching and have ramped up
the production of Bandit gear accordingly, so expect to see an increase in
Bandit gear drops when playing Borderlands 2 while connected to the internet.
But watch out! Reports suggest an increased population of Badass Psychos in
Lynchwood, Thousand Cuts and Eridium Blight.